Nanosheet Films Research Articles

Molecular-Scale Manipulation of Layer Sequence in Heteroassembled Nanosheet Films toward Oxygen Evolution Electrocatalysts.

Flocculation or restacking of different kinds of two-dimensional (2D) nanosheets into heterostructure nanocomposites is of interest for the development of high-performance electrode materials and catalysts. However, lacking a molecular-scale control on the layer sequence hinders enhancement of electrochemical activity. Herein, we conducted electrostatic layer-by-layer (LbL) assembly, employing oxide nanosheets (e.g., MnO2, RuO2.1, reduced graphene oxide (rGO)) and layered double hydroxide (LDH) nanosheets (e.g., NiFe-based LDH) to explore a series of mono- and bilayer films with various combinations of nanosheets and sequences toward oxygen evolution reaction (OER). The highest OER activity was attained in bilayer films of electrically conductive RuO2.1 nanosheets underlying catalytically active NiFe LDH nanosheets with mixed octahedral/tetrahedral coordination (NiFe LDHTd/Oh). At an overpotential of 300 mV, the RuO2.1/NiFe LDHTd/Oh film exhibited an electrochemical surface area (ECSA) normalized current density of 2.51 mA cm-2ECSA and a mass activity of 3610 A g-1, which was, respectively, 2 and 5 times higher than that of flocculated RuO2.1/NiFe LDHTd/Oh aggregates with a random appearance of a surface layer. First-principles density functional theory calculations and COMSOL Multiphysics simulations further revealed that the improved catalytic performance was ascribed to a substantial electronic coupling effect in the heterostructure, in which electrons are transferred from exposed NiFe LDHTd/Oh nanosheets to underneath RuO2.1. The study provides insight into the rational control and manipulation of redox-active surface layers and conductive underlying layers in heteroassembled nanosheet films at molecular-scale precision for efficient electrocatalysis.

Heterometallic Benzenehexathiolato Coordination Nanosheets: Periodic Structure Improves Crystallinity and Electrical Conductivity.

Coordination nanosheets are an emerging class of 2D, bottom-up materials having fully π-conjugated, planar, graphite-like structures with high electrical conductivities. Since their discovery, great effort has been devoted to expand the variety of coordination nanosheets; however, in most cases, their low crystallinity in thick films hampers practical device applications. In this study, mixtures of nickel and copper ions are employed to fabricate benzenehexathiolato (BHT)-based coordination nanosheet films, and serendipitously, it is found that this heterometallicity preferentially forms a structural phase with improved film crystallinity. Spectroscopic and scattering measurements provide evidence for a bilayer structure with in-plane periodic arrangement of copper and nickel ions with the NiCu2 BHT formula. Compared with homometallic films, heterometallic films exhibit more crystalline microstructures with larger and more oriented grains, achieving higher electrical conductivities reaching metallic behaviors. Low dependency of Seebeck coefficient on the mixing ratio of nickel and copper ions supports that the large variation in the conductivity data is not caused by change in the intrinsic properties of the films. The findings open new pathways to improve crystallinity and to tune functional properties of 2D coordination nanosheets.

A novel ZnS nanosheets-based triboelectric nanogenerator and its applications in sensing, self-powered electronics, and digital systems

The development of triboelectric nanogenerators (TENGs) based on inexpensive inorganic materials has attracted significant attention to envisage next-generation self-powered electronic devices and sensors. In this research work, the fabrication of a triboelectric nanogenerator (TENG) based on ZnS nanosheets arrays was investigated for the first time. This TENG was fabricated with ZnS nanosheets films, polydimethylsiloxane (PDMS) as active tribo-layers. The originality of this work lies in the choice of materials; pure ZnS nanosheets and PDMS-Al cover foils. By hand excitation force, the developed TENG (5 ×5 cm2) produced an output voltage and a short-circuit current of ~8 V and ~7.12 µA respectively. In addition, the present TENG with pure ZnS nanosheets on Al substrate produced an output voltage almost twice than TENG that involved only Al substrate. In this current study, introducing ZnS nanosheets on Al substrate increased the surface area and roughness, resulting in improved performance. The study of TENG parameters confirms that the TENG (10 ×10 cm2) with 2 cm spacing between tribo layers, applied force frequency of ~ 4–5 Hz were optimum to obtain the maximum output voltage of ~33 V. The high stability of TENG was confirmed by testing TENG response over 1000 cycles. Further, TENG was used to power portable electronic devices such as a digital watch, thermometer, calculator, and 64 LEDs when coupled to a capacitor. Finally, TENG was demonstrated for sensing force and pressure, TENG output response was used as a clock pulse for the digital circuits. The proposed TENG is easy to handle, simple and economical, and ZnS-based TENG's performance can be improved using other tribo-materials instead of PDMS.

Antioxidant Triggered Metallic 1T' Phase Transformations of Chemically Exfoliated Tungsten Disulfide (WS2 ) Nanosheets.

Developing facile methods for inducing phase transformation between metallic and semiconducting 2D transition metal dichalcogenide (TMDC) materials is crucial toward leveraging their use in cutting-edge energy devices. Herein, 2H-to-1T' phase transformations in chemically exfoliated Tungsten Disulfide (WS2 ) nanosheet films, triggered by antioxidants toward highly conductive 2D TMDC electrode materials, are introduced. It is found that antioxidants cause residual LiOx compounds to reduce to Li metal, subsequently inducing 1T' phase transformations in layered WS2 nanosheets, resulting in significantly enhanced conductivity across the overall films. Both thermoelectric devices and supercapacitors are fabricated utilizing the highly conductive 1T' phase WS2 nanosheet films as a working electrode, allowing for outstanding performance due to the increased conductivity of the WS2 nanosheet films. The method constitutes a facile approach toward the use of chemically exfoliated 1T' TMDC nanosheets for highly efficient energy device applications.

High thermal conductivity and increased thickness graphene nanosheet films prepared through metal ion-free route

With the miniaturization and integration of electronic devices heat conduction becomes a serious problem. Graphene films catch research's attention because of its excellent thermal performance and graphene oxide (GO) has been used as the most common precursor to prepare graphene films. But mostly film fabricated from GO is thinner than 30 μm and much thicker films are required to meet certain requirements. Also taking GO as raw material has many disadvantages such as the introduction of massive concentrated sulfuric acid and metal ions, huge weight loss in heat treatment and so on. Herein, we propose a new strategy to prepare graphene nanosheet films (GNFs) with a thickness of 100 μm by vacuum filtration of expand graphite through weak oxidation (WEG). Unlike common strategy, WEG without any metal ions introduced instead of GO is chosen as our raw material. The addition of nonionic surfactant and the employment of microfluidization can stabilize WEG dispersion. After graphitization at 2800 °C WEGF is transferred to GNF. The obtained 100 μm-thick film possesses a decent in-plane thermal conductivity (TC) of 760 W/mk and electrical conductivity (EC) of 5.2×10 5 S/m. Thick films with high TC can guarantee passing more heat flux and fill in larger gaps inside devices.

A generic and non-enzymatic electrochemical biosensor integrated molecular beacon-like catalyzed hairpin assembly circuit with MOF@Au@G-triplex/hemin nanozyme for ultrasensitive detection of miR-721

MicroRNAs (miRNAs) have been extensively studied as circulating biomarkers for early diagnosis and prognosis of many human diseases. However, it has been found challenging to accurately detect and quantify the trace amounts of miRNAs in biological samples. Herein, we propose a generic and non-enzymatic electrochemical strategy integrated molecular beacon-like catalyzed hairpin assembly (mCHA) circuit with MOF@Au@G-triplex/hemin nanozyme for ultrasensitive detection of miR-721 (a novel diagnostic biomarker of acute myocarditis). Nitro-functionalized MIL-101 functions as an ideal nanocatalyst and nanocarrier to facilitate efficient immobilization of G-triplex/hemin DNAzyme, to form signal probes. Tetrahedral nanostructured DNA probes self-assemble onto the Au nanoparticles/proton-functionalized graphitic carbon nitride nanosheets films, to fabricate a coordinated sensing interface. A mCHA circuit is designed to convert and amplify each target to DNA duplexes, which cause signal probes anchored on the sensing interface and produce an enhanced electrochemical signal. With the assistance of the mCHA circuit, double-amplified nanozymes and sensing interface for signal amplification, this biosensor had a low detection limit of 0.25 fM and high specificity. The proposed biosensor has been successfully used in miR-721 detection in real biological samples, which provided a promising potential method for acute myocarditis early diagnosis.

Nickel Sulfate as an Influential Precursor of Amorphous High-Valent Ni(III) Oxides for Efficient Water Oxidation in Preparation via a Mixed Metal-Imidazole Casting Method

Nickel-based materials are promising electrocatalysts for an alkaline oxygen evolution reaction (OER), which is indispensable for developing water-splitting systems to produce hydrogen as a carbon-neutral fuel. Different NiOx films adhered rigidly on nickel foam (NF) and fluorine-doped tin oxide substrates were prepared via a mixed metal-imidazole casting method from precursor solutions containing Ni salts with four different counter anions of SO42–, NO3–, Cl–, and CH3COO– (Ac) in methanol/1-methyimidazole mixed solvents (3:1) followed by calcination at 450 °C. The counter ions of Ni salts are significantly influential on the structure and characteristics of the formed NiOx films. In the case of the film (SO4-NiOx) prepared from the NiSO4 precursor, an amorphous NiIIIOx nanosheet film was formed in contrast to face-centered cubic NiIIO crystalline nanoparticle films formed using the other precursors, under the same conditions. The special characteristics of the SO4-NiOx film are caused by the inhibition effect of the SO42– ions on the thermochemical formation of NiIIO from the precursor complex, leading to the formation of a NiIIIOx intermediate. The SO4-NiOx/NF electrode demonstrated superior OER performance with an overpotential, η10 = 228 mV at a current density of 10 mA cm–2 in alkaline KOH solutions, which is lower by 145∼165 mV than those (η10 = 373∼393 mV) of the other NiOx/NF electrodes. The OER performance of the SO4-NiOx/NF electrode compares advantageously with that of state-of-the-art Ni-based anodes reported to date.

Nanosheet-Assembled MnO2-Integrated Electrode Based on the Low-Temperature and Green Chemical Route

The development of superior electrochemical energy-storage devices designed through a facile, cost-efficient, and green synthesis technique is the key to addressing the intermittent nature of renewable energy sources such as solar and wind energy. In our present work, we design a simple, surfactant-free, and low-temperature chemical strategy to prepare novel integrated, MnO2 composite electrodes with two-dimensional (2D) nanosheet film directly supported on three-dimensional (3D) conductive nickel foam. Benefiting from the specific 2D nanosheet architecture to provide a large interfacial contact area and highly conductive metal scaffolds to facilitate fast electron transfer, the novel nanosheet-assembled MnO2-integrated electrodes exhibit higher specific capacitance of 446 F g−1 at the current density of 1 A g−1 compared with nanostructured MnO2 and commercial MnO2 powder electrodes. More importantly, the as-synthesized devices are able to achieve an outstanding cycling performance of 95% retention after 3000 cycles. The present work, which is based on the low-temperature chemical route to deposit active materials on the conductive substrate, provides new insights into designing a binder-free supercapacitor system to improve the specific capacitance, cycling, and rate performance as next-generation, energy-storage devices.

A simple and low-cost triboelectric nanogenerator based on two dimensional ZnO nanosheets and its application in portable electronics

The exploration of new triboelectric materials is considered a significant research area to reduce the cost and complexity of the triboelectric nanogenerator (TENG) device and improve its energy conversion efficiency. In this report, a new triboelectric material pair has been demonstrated to prepare an inexpensive and high-performance TENG. A low-cost hot plate-assisted hydrothermal process is used to prepare the ZnO nanosheets on an aluminum substrate. TENG is made using ZnO nanosheet film, PET/ITO, and operates in vertical contact separation mode. The proposed TENG generates electricity through contact electrification and electrostatic induction. The fabricated TENG is tested for the switching polarity test and confirmed the output voltage generated by TENG alone. The TENG can deliver an open-circuit voltage and short-circuit current of ~ 4.9 V and 10 µA, respectively, for repeated hand tapping.Further, the performance of the proposed TENG is tested under resistive loads, and the maximum power density of 1 µW/cm2 observed at a load resistance of 5 MΩ. Similarly, TENG is also tested under capacitive loads and found the maximum energy stored value of 16.9 μJ at the load capacitance of 47 μF. In addition, the effect of different frequencies of the applied force and device size on the TENG response is studied. The TENG can light up 3 LEDs instantaneously and power the digital watch and 24 LEDs using an energy storage element. The present TENG shows a low-cost and straightforward process and can harvest energy from low-frequency bio-mechanical vibrations. The proposed TENG has potential applications in self-powered electronic devices and systems.

Direct fabrication of high-performance multi-response e-skin based on a graphene nanosheet film

With the increasing popularity of wearable devices, lightweight electronic skin (e-skin) has attracted significant attention. However, current fabrication technologies make it difficult to directly fabricate sensing materials on flexible substrates at low temperatures. Hence, we propose a flexible graphene nanosheet-embedded carbon (F-GNEC) film, which is directly grown on a flexible substrate using an electron cyclotron resonance low-temperature sputtering system. The direct batch manufacturing of e-skin is obtained by the unique plasma generation mode of electron cyclotron resonance and the polariton energy transfer mode between the plasma and substrate surface. The F-GNEC film contains a large number of graphene nanosheets grown vertically and the graphene edges can serve as electron capture centers, thereby enabling the multi-response properties. We achieve a high gauge factor of 14,699 under a tensile strain of ε = 0.5% and the changing rate of the resistance reaches to 113.2% when the e-skin is bent to 120°. Furthermore, the e-skin achieves a photocurrent of 1.2 μA under 532 nm laser illumination. The F-GNEC film exhibits a sensitive temperature response and achieves a coefficient of -0.58%/°C in a wide temperature range (30-100 °C). The directly fabricated F-GNEC film-based e-skin is stable and firm and exhibits multi-response detection capabilities, which enable its potential application in virtual reality technology and flexible robots.

In situ preparation of two-dimensional ytterbium ions doped all-inorganic perovskite nanosheets for high-performance visual dual-bands photodetectors

Two-dimensional (2D) all-inorganic halide perovskites exhibit impressive optical and electrical properties, which are attracting extensive current interests. Rare earth (RE) ions doping is a significant method to adjust their optical, electrical properties and realize various applications. However, 2D RE ions-doped perovskite crystals have been rarely reported. Herein, we reported the synthesis of novel 2D all-inorganic perovskite CsPbClxBr3−x nanosheets (NSs) doped with RE ions. The octylamine (OLAm) with short carbon chains is used to tune the growth orientation for the preparation of 2D perovskite NSs. The morphology of the NSs can be adjusted by varying the ratio of shorter ligands to longer ligands and changing the temperature. The Yb3+ ions doped CsPbClBr2 NSs demonstrate an excitonic emission of perovskite host and a quantum cutting emission of Yb3+ ions at 985 nm with the optimal photoluminescence quantum yield (PLQY) of 128%. The results of femtosecond time-resolved transient absorption spectroscopy and DFT calculations indicate that the defect density of NSs is largely decreased and the photostability is enhanced induced by the passivation effect of Yb3+ ions. The photodetector (PD) based on lateral assembled Yb3+ ions doped CsPbClBr2 NS film is fabricated, which demonstrates a high responsivity and dual-band detection capability. The as-fabricated PDs are sensitive to both UV and NIR light, showing the responsivity of 1.96 A W−1, 0.12 mA W−1, the detectivity of 5 × 1012, 2.15 × 109 Jones at 440 nm and 980 nm, respectively. Finally, based on an imaging system with a PD array and a data analysis system, visual photoelectric detection is realized, and high-contrast images of the measured UV and NIR light are displayed. This work paves the way to tune the properties of 2D perovskite materials and develop high-performance optoelectronic devices.

Controlled Release of Molecular Intercalants from Two-Dimensional Nanosheet Films.

Solution co-deposition of two-dimensional (2D) nanosheets with chemical solutes yields nanosheet-molecular heterostructures. A feature of these macroscopic layered hybrids is their ability to release the intercalated molecular agent to express chemical functionality on their surfaces or in their near surroundings. Systematic design methods are needed to control this molecular release to match the demand for rate and lifetime in specific applications. We hypothesize that release kinetics are controlled by transport processes within the layered solids, which primarily involve confined molecular diffusion through nanochannels formed by intersheet van der Waals gaps. Here a variety of graphene oxide (GO)/molecular hybrids are fabricated and subject to transient experiments to characterize release kinetics, locations, and mechanisms. The measured release rate profiles can be successfully described by a numerical model of internal transport processes, and the results used to extract effective Z-directional diffusion coefficients for various film types. The diffusion coefficients are found to be 8 orders of magnitude lower than those in free solution due to nanochannel confinement and serpentine path effects, and this retardation underlies the ability of 2D materials to control and extend release over useful time scales. In-plane texturing of the heterostructured films by compressive wrinkling or crumpling is shown to be a useful design tool to control the release rate for a given film type and molecular intercalant. The potential of this approach is demonstrated through case studies on the controlled release of chemical virucidal agents.

Ball-Milling Exfoliation of Hexagonal Boron Nitride in Viscous Hydroxyethyl Cellulose for Producing Nanosheet Films as Thermal Interface Materials

Boron nitride nanosheets (BNNS) exfoliated by physical or chemical methods frequently exhibit poor dispersity in common solvents due to incomplete exfoliation and a low degree of functionalization,...

Vertical Few-Layer WSe2 Nanosheets for NO2 Sensing

WSe2 has been widely used in NO2 gas sensors in recent years, but it still suffers from low responsiveness and slow reaction kinetics. Herein, we used the chemical vapor deposition method to synthesize a vertically grown few-layer WSe2 (3D-WSe2) nanosheet film. Three-dimensional-WSe2 is transformed into vertical growth by introducing a TiO2 buffer layer and exposes much more edge active sites to improve gas sensitivity. As a result, it has not only high crystallinity and few defects but also a high response to NO2 (34.6% at 1 ppm), a fast response time (66 s), a short recovery time (17 min), a low limit of detection (4 ppb), excellent stability, and gas selectivity at room temperature.

One-Pot Synthesis of Chlorophyll-Assisted Exfoliated MoS2/WS2 Heterostructures via Liquid-Phase Exfoliation Method for Photocatalytic Hydrogen Production.

Developing strategies for producing hydrogen economically and in greener ways is still an unaccomplished goal. Photoelectrochemical (PEC) water splitting using photoelectrodes under neutral electrolyte conditions provides possibly one of the greenest routes to produce hydrogen. Here, we demonstrate that chlorophyll extracts can be used as an efficient exfoliant to exfoliate bulk MoS2 and WS2 to form a thin layer of a MoS2/WS2 heterostructure. Thin films of solution-processed MoS2 and WS2 nanosheets display photocurrent densities of −1 and −5 mA/cm2, respectively, and hydrogen evolution under simulated solar irradiation. The exfoliated WS2 is significantly more efficient than the exfoliated MoS2; however, the MoS2/WS2 heterostructure results in a 2500% increase in photocurrent densities compared to the individual constituents and over 12 h of PEC durability under a neutral electrolyte. Surprisingly, in real seawater, the MoS2/WS2 heterostructure exhibits stable hydrogen production after solar illumination for 12 h. The synthesis method showed, for the first time, how the MoS2/WS2 heterostructure can be used to produce hydrogen effectively. Our findings highlight the prospects for this heterostructure, which could be coupled with various processes towards improving PEC efficiency and applications.

The reversible wetting transition between superhydrophilicity and superhydrophobicity of tremella-like CuxO@CuxS nanosheets prepared by one-step anodization and the application of on-demand oil/water separation

A simple one-step anodizing process is developed for the large-scale preparation of the tremella-like CuxO@CuxS nanosheet films on Cu mesh, and the prepared organic-free CuxO@CuxS nanosheet films on Cu mesh exhibit excellent mechanical stability and corrosion resistance. The fresh organic-free tremella-like CuxO@CuxS nanosheets have the superhydrophilicity and underwater superoleophobicity. But after storage in atmosphere for about 6 days under room temperature, the wettability is gradually transformed into superhydrophobicity and superlipophilicity. Importantly, the wettability can turn back again to the superhydrophilicity and underwater superoleophobicity after the annealing process at 200 °C in air environment. So the stable reversible wetting transition is realized, then the transition mechanism has been investigated by the detailed X-ray photoelectron spectroscopy (XPS) characterization, and is mainly attributed to the production of hydroxide radicals and adsorption of C-C/C-H species on the CuxO@CuxS nanosheet surface. Lastly, the prepared tremella-like CuxO@CuxS nanosheets on copper mesh have been successfully applied for on-demand oil/water separation with high efficiency.

Construction of Multilayer Films and Superlattice- and Mosaic-like Heterostructures of 2D Metal Oxide Nanosheets via a Facile Spin-Coating Process.

This study reports a design of a variety of nanostructured films of 2D oxide nanosheets. We systematically examined the deposition of perovskite-type Ca2Nb3O10- nanosheets by spin-coating their dimethyl sulfoxide dispersion. Neat and homogeneous monolayer tiling was attained on various substrates by selecting an optimum rotation speed, which was dependent on the nanosheet concentration. Repeating the optimized spin-coating process allowed for layer-by-layer deposition of the nanosheets into multilayer films with a designed layer number. Vertical superlattice heterostructures could also be assembled by alternately spin-coating the suspensions of Ca2Nb3O10- and Ti0.87O20.52- nanosheets. Furthermore, spin-coating of a mixed suspension of Ca2Nb3O10- and Ti0.87O20.52- nanosheets led to a mixed mosaic-like monolayer of these two nanosheets. The present study thus demonstrated spin-coating as a facile and powerful route to construct various nanostructures based on 2D oxide nanosheets.

A simple and low-cost approach for the synthesis and fabrication of ZnO nanosheet-based nanogenerator for energy harvesting and sensing

Reducing the cost of the synthesis process and device fabrication plays an essential role in modestly developing products. In the present report, a simple and low-cost approach for the synthesis of ZnO nanosheets and the fabrication of a piezoelectric nanogenerator is developed. The ZnO nanosheets are synthesized by hot plate assisted hydrothermal method and characterized for their morphology, crystallinity, composition. The fabricated nanogenerator device produced an open-circuit voltage of ∼220 mV upon finger tapping. The series connection of seven such devices produced an open-circuit voltage of ∼1.2 V. The ZnO nanosheets films synthesized at a growth temperature of 85 °C for a growth duration of 4 h are found to be optimum parameters for making the nanogenerator device with high output. The nanogenerator response is recorded for different frequencies of finger tapping and different finger-tapping pressures. Further, the fabricated nanogenerator exhibited a stable output response over 1100 cycles confirms the high durability of the fabricated device. The fabricated nanogenerator is explored further for pressure sensing application.

Electrochemically Exfoliated Graphite Nanosheet Films for Electromagnetic Interference Shields

Electrochemical exfoliation of graphite is one of the most efficient and easiest processes to produce high-quality graphene materials. In this study, the efficiency of exfoliation methods for graphite to develop graphene-based electromagnetic interference (EMI) shields with high electrical conductivity was investigated. Exfoliation of graphite was performed in four aqueous solutions of inorganic salts of Na2SO4, (NH4)2SO4, NH4NO3, and (NH4)2HPO4, and the electrochemically exfoliated graphene (EEG) was thoroughly screened to separate out the more defective and small sheets. A 30 μm thick film composed of stacked and overlapped co-doped EEG sheets prepared in (NH4)2SO4 had a room-temperature electrical conductivity of 28 400 S/m and an EMI shielding effectiveness (EMI SE) of ∼62 dB in the X-band frequency (8.2–12.4 GHz), without any reduction of EEG sheets. These are both high values compared to values reported in the literature for “graphene” films with comparable thickness. This is an excellent EMI SE for a shield thickness of just 30 μm, compared to the very thick initial graphite sheet’s EMI SE of ≈70 dB with a thickness of 1.5 mm (50 times thicker). An original finding in this paper is that using the (NH4)2HPO4 electrolyte, we were able to prepare thermally stable EEG films with excellent EMI performance (shielding effectiveness of ∼50 dB after 3-day exposure to 500 °C in air). These high values for overall EMI shielding and electrical conductivity confirm the feasibility of electrochemical exfoliationfor high-performance EMI shields; i.e. it is possible to use a method that does not involve treatment with harsh chemicals or oxidizers and does not require high energies or high temperatures.

Active‐Matrix‐Based Flexible Optical Image Sensor

AbstractOwing to the demand for the development of Internet of things devices, multiple sensor platforms are of great interest to society and its future electronics. One of these emerging devices is a mechanically flexible sensor system that can attach and conform to nonplanar surfaces, unlike conventional inflexible sensor chips. To realize this concept, a variety of flexible sensor systems must be developed from materials to system integrations. This study proposes a flexible sensor system as one of the candidates: an active‐matrix‐based flexible optical image sensor that uses a stacked nanosheet film formed by a solution process and transistors. The results show that the sensor can be utilized as an optical imager because it detects enough optical stimuli. In addition to the sensitivity, the mechanical flexibility of the active‐matrix optical sensor is tested, and the results exhibit good electrical stability even after 1000 bending cycles and 0.85 cm bending radius. The mapping of light distribution is successfully demonstrated under both flat and curved conditions. This flexible optical sensor array shows the high possibility to image the light distribution for high‐resolution and low power mapping realized by active matrix circuit integration.